Question

find the sum of first 30terms of arithmetic progession 2+5+8+.............​

Answer 1

Answer:

a=2. ,d=5-2=3. ,n=30

Sn=n/2×{2a+(n-1)d}

S=30/2{2×2+(30-1)3}

S=15{4+29×3}

S=15×{4+87}

S=15×91

S=1365